Stuffing box

Packing in the stuffing-boxes, through which the piston-rods pass at the end of the cylinder, and so arranged to keep the cylinders steam-tight, at times become loose or displaced, and in such conditions steam may pass with considerable violence out of the cylinder by way of the stuffing-box, giving an acoustic effect somewhat resembling that of an engine with cylinder-cocks open, except that the noise heard is intermittent and not practically continuous, as when the cylinder cocks are open.

The regulator in the dome is of the vertical grid type, operated by an external pull rod connected to a transverse shaft which works through a stuffing box on the second barrel plate.